With vitreous prolapsed into the anterior chamber, we must perform a vitrectomy before placing the IOL in the eye. In this case we will use a three-piece IOL which will be placed with the haptics in the sulcus and the optic captured behind the capsulorhexis. This placement allows for great long-term stability and it re-establishes the barrier between the anterior segment and vitreous cavity. This surgery is performed by a young surgeon in residency training and the final results are very good.
This is the step-by-step guide for performing this anterior vitrectomy and IOL placement:
- Step 1: Abandon the main incision. This incision is not suitable for bimanual small gauge (23 gauge) vitrectomy because it is too wide and it will leak during the procedure.
- Step 2: Make a second paracentesis incision to provide access for the bimanual instrumentation. You may need to make these slightly wider depending on your set-up.
- Step 3: Set-up and prime your phaco machine to get the vitrectomy cutter ready to be used. Also at this time, ask for triamcinolone to be opened on the field.
- Step 4: Put the machine into Anterior Vitrectomy Mode (not I/A Cut Mode). We want the foot pedal positions to be: 1 irrigation, 2 vitrectomy cutting action, and 3 aspiration.
- Step 5: Choose a high cutting rate of at least 1000 cuts per minute and a moderate flow rate (20 to 30 cc/min depending on your instrument flow). Try a vacuum level of 200-400 mmHg
- Step 6: Place a small amount of triamcinolone into the anterior chamber and swirl it around using the infusion hand-piece or injection of balanced salt solution.
- Step 7: Enter the anterior chamber with the vitrectomy cutter and look for the prolapsed vitreous that is stained with triamcinolone. Stay centrally in the eye at the lens plane.
- Step 8: Take your time removing the prolapsed vitreous. This takes time, usually 5 to 10 minutes. Avoid putting traction on the vitreous or pulling it.
- Step 9: Re-inject another small aliquot of triamcinolone to re-stain the vitreous. Since the triamcinolone particles only stain the outside of the prolapsed vitreous, more must be used
- Step 10: Sweep any prolapsed vitreous from the incisions back into the eye and completely remove with the vitrectomy cutter.
- Step 11: Once the anterior vitrectomy is complete and you have confirmed that the anterior segment is clear, inspect and determine the degree of capsular support available.
- Step 12: Viscoleastic is lightly placed in the anterior chamber and a small amount under the iris in order to open the ciliary sulcus area.
- Step 13: The three-piece IOL is inserted in to the eye and the haptics are placed in the sulcus with care taken to avoid entrapment of iris tissue.
- Step 14: The optic is then pushed through the capsulorhexis, much like putting a button through a buttonhole in a shirt.
- Step 15: The main incision is sutured closed and then the bimanual instrumentation is used to remove the viscoelastic from the eye.
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